The other potential reuse opportunities
are presented by the cash flow report atomic service (A1) and the monthly statements composite
service (C2). Both reside in the overlapped section as well.
USE CASE H: LOOSELY COUPLED STRATEGY. Loose coupling implementations can be typically
attained by decomposition operations that break down large coarse-grained entities. Exhibit 8.11
illustrates a problem domain that identifies a very coarse-grained composite service that aggregates
three major composite services, each of which contains its own internal services. A decomposition
operation would be required to separate these entities into smaller components: composite service
166 Ch. 8 Service-Oriented Analysis Modeling
Service CO2
Service CO5
Service CO1
Problem Analysis Solution Proposition
A7
A5
A1
A2
A4
A6
Atomic
Atomic
Atomic Atomic
Atomic
Composite
Composite
Composite
Service CO3
A3 Atomic
Composite
Composite
Service CO4
A9
A8 Atomic
Atomic
A10 Atomic
Atomic A10
Composite
Service CO1
Service CO3
Atomic
A3 Atomic
Composite
Service CO4
A7
A5 A4
A6
Atomic
Atomic Atomic
Composite
A9 A8 Atomic Atomic
Atomic
Service CO5
Atomic
EXHIBIT 8.11 USE CASE H: REQUIREMENTS
CO1, atomic service CO3, composite service CO4, and composite service CO5. Note the following
major three transformation activities:
1. The composite service CO1 retains only the atomic service A10.
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